// Problem: 
// Contest: 
// URL: 
// Memory Limit: 
// Time Limit: 
// #pragma GCC optimize("Ofast")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#include<bits/stdc++.h>
using namespace std;
#define int long long
inline int read(){
	int s=0,w=1;
	char ch=getchar();
	while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
	while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
	return s*w;
}
struct node
{
	int a,b;
};
bool cmp(node x,node y)
{
	if(x.a>y.a)return 1;
	else if(x.a==y.a)
	{
		return x.b>y.b;
	}
	else return 0;
}
signed main()
{
	int t=1;
	cin>>t;
	while(t--)
	{
		int n,ans=0;
		cin>>n;
		vector<node> v(n+1);
		for(int i=1;i<=n;i++)
		{
			cin>>v[i].a;
		}
		for(int i=1;i<=n;i++)
		{
			cin>>v[i].b;
		}
		sort(v.begin()+1,v.end(),cmp);
		for(int i=1;i<=n;i++)
		{
			//cout<<v[i].a<<" "<<(v[i].b-(i-1))<<endl;
			ans+=v[i].a*(v[i].b-(i-1));
		}
		cout<<ans<<endl;
	}
	return 0;
}
